They operate from Sri Lanka to South Korea and Ireland to Iran, and have done so for decades. But only a handful of rail agencies in the United States operate this type of train, partly because U.S. rail regulations bar DMUs from running on tracks used by traditional commuter rail.

Siemens, the German company that built the Desiro Classic DMU trains for the Sprinter system, has sold more than 600 of that type in several countries, according to Siemens spokeswoman Elizabeth Cho.

Aside from the 12 trains it made for North County, Siemens hasn’t sold a single Desiro Classic in the United States and has no pending orders for that model in this country, Cho said. Only a handful of rail agencies in North America operate DMUs, including those in Ottawa, Canada; Austin, Texas; and Camden, N.J.

Former Escondido Mayor Lori Holt Pfeiler, who served on the transit district’s board through much of the 1990s, said choosing a DMU model was important because it kept expenses down as officials sought federal funding for the Sprinter network. The Siemens purchase ultimately cost $50 million.

Pfeiler said the district’s officials believed the maintenance history of DMUs was strong. She expressed disappointment with the current rotor problem.

While Siemens designed and constructed the Sprinter’s complex braking system, it did not build the rotors that wore out unexpectedly. Those were made by Faiveley Transport of France.

Moving forward

By the end of April, the North County Transit District hopes to receive its full set of replacement rotors from the Slovenian company Kovis. At that time, the agency also expects to announce a “relaunch” date for the Sprinter.

For now, the agency’s replacement buses and some contracted vans and taxis continue to ferry former Sprinter riders across North County.

Looking back at the decision to buy the unique trains, Ritter, who is now Vista’s mayor, said she’s surprised the transit agency didn’t keep replacement rotors on hand.

Otherwise, she said, she has few regrets about backing the Sprinter purchase.

“I think we made the best choice at the time,” she said. “And (the trains) have served us very well — until the brake problem.”